docs: def _prefer_package(self, package):
          """ Prefer a serializtion handler over other handlers.
  
          :param str package: The name of the package to use
          :raises ValueError: When the given package name is not one of the available
              supported serializtion packages for this handler
          :return: The name of the serialization handler
          :rtype: str
          """
  
          if isinstance(package, str) and package != self.imported:
              if package not in self.packages:
                  raise ValueError(
                      f"preferred package {package!r} does not exist, allowed are "
                      f"{self.packages!r}"
                  )
              # clear out current serialization handler (if exists)
              if hasattr(self, "_handler"):
                  del self._handler
              # manually update imported handlers with a given preference
              self._imported = self._discover_import(prefer=package)
              return package
          return self.imported